The biological perspective views behavior and mental processes as ultimately resulting from biological influences, particularly evolutionary processes and genetic factors. Historically, philosophers and scientists have explored the relationship between the physical body and mental processes. In the 18th-19th centuries, thinkers like Descartes, James, and Dunlap contributed to understanding the biological underpinnings of psychology. The biological perspective examines behavior through comparative studies, physiology, and inheritance. Major theories like dualism, materialism, heredity, and natural selection helped develop this perspective. Biological psychology analyzes behaviors in relation to genetics, the nervous system, neurotransmitters, and other biological factors.

1. Biological Perspective
Instructor: Rustam Ali

2. Schools and Perspectives in Psychology
• Structuralism
• Functionalism
• Behaviorism
• Gestaltism
• Psychodynamic
• Biological Perspective
• Cognitive Perspective
• Existential Perspective
• Humanistic Perspective
• Cultural Perspective
• Islamic Perspective

3. Historically Roots
• Biopsychology as a specialized discipline gained its importance during
18th and 19th centuries.
• Eminent philosopher Rene Descartes propounded the physical model
for explaining the behavior of animals and humans.
• According to him, the Pineal gland which exists in the brain of many
organisms is the point of connection between body and brain.
• Descartes was also responsible for introducing the concept of reflexes
which led to muscle responses, though this was later denied by the
researchers with an argument that spinal cord is responsible for
muscular responses.

4. 18th and 19th centuries
• William James in his works “The Principles of Psychology”, 1890, tried to
highlight that the study of psychology should be aligned with an understanding of
the biological parameters.
• Knight Dunlap first coined the term “psychobiology” in his work “An Outline of
Psychobiology” in 1914.
• In a nutshell, the philosophers were engaged in understanding the relationship
between the physical and mental worlds.
• Ever since 18th and 19th centuries, the researchers have contributed some
important research findings which explain the functioning of human brain and
unveiled crucial findings on neurons, functioning of the nervous system and
neuro-transmitters.

5. Methods which relate biological to psychology
• The biological perspective is relevant to psychology through three areas of
investigation.
• Comparative method: by studying different animal species, their behavior under similar
stimuli can be compared to human data enhancing the understanding of human
behaviors.
• Physiology: how the nervous system and hormones work, how the brain functions, how
changes in structure and/or function can affect behavior. For example, we could ask
how prescribed drugs to treat depression affect behavior through their interaction with
the nervous system.
• Inheritance: what an animal inherits from its parents, mechanisms of inheritance
(genetics). For example, we might want to know whether high intelligence is inherited
from one generation to the next.

6. Theories Leading to Biological Perspective
• There are four main theories which contributed to the development of the biological
perspective of psychology.
• Dualism: A theory developed by Descartes. He determined that although the body and
mind are separate, they do interact through the brain's pineal gland. This theory has
been disregarded by many psychologists.
• Materialism: This theory assumes a physical aspect to all behavior. It is based on
animal and human genetics studies suggesting genes evolved over long periods of time.
• Heredity: This theory assumes that behavioral traits result from the passing on of
characteristics through gene transfer from one generation to the next.
• Natural Selection: This theory was developed by Charles Darwin who proposed the idea
that random variations in organisms led to better reproductive success ensuring the
passing on of these traits to subsequent generations.

7. Consider an issue like aggression
• The psychoanalytic perspective might view aggression as the result of
childhood experiences and unconscious urges.
• The behavioral perspective considers how the behavior was shaped
by association, reinforcement, and punishment.
• The biological viewpoint, on the other hand, would involve looking at
the biological roots that lie behind aggressive behaviors.
• Someone who takes the biological perspective might consider how
certain types of brain injury might lead to aggressive actions.
• Or they might consider genetic factors that can contribute to such
displays of behavior.

8. Theories required a unifying perspective
• The development of these theories required a unifying perspective explaining the connection
between psychology and physiology.
• Almost every human behavior and mood is analyzed by the biological perspective for its
physiological origin. Criminal behavior, depression, happiness, and personality disorders have
been studied extensively by this perspective.
• Happiness Criminal behavior: It was widely held by bio-psychologists that criminal behavior
was due largely to heredity and many were in favor of eugenics, a means, they thought, to
improve the human species through compulsory sterilization of criminals, the mentally
retarded, and others thought to be social misfits due to the inheritance of undesirable traits, is
thought to be due to the quality of experience offered by our nervous system.
• Depression results from a traumatic situation which alters a person's nervous system leading to
the secretion or inhibition of secretion of specific neurotransmitters.
• A person's personality will determine his/her perception of the experience.

9. Psychology as biopsychology
• This field of psychology is often referred to as biopsychology or physiological psychology.
• This branch of psychology has grown tremendously in recent years and is linked to other areas
of science including biology, neurology, and genetics.
• The biological perspective is essentially a way of looking at human problems and actions.
• The study of physiology and biological processes has played a significant role in psychology
since its earliest beginnings.
• Charles Darwin first introduced the idea that evolution and genetics play a role in human
behavior.
• Natural selection influences whether certain behavior patterns are passed down to future
generations.
• Behaviors that aid in survival are more likely to be passed down while those that prove
dangerous are less likely to be inherited.

10. Biological Perspective
• Biological Perspective presented by McDougall
• Explained biological functions as the basis of behaviour
• The biological perspective states that all thoughts, feeling & behavior ultimately
have a biological cause.
• Major Areas of Biological perspective
• Genetics
• Immune system
• Human Nervous System[ brain]
• Neuro-transmitters
• Glands

11. Genetics
• Genetics is a branch of biology concerned with the study of genes,
genetic variation, and heredity in organisms.
• Biological perspective study how genes affect behavior.
• Now that the human genome is mapped, perhaps, we will someday
understand more precisely how behavior is affected by the DNA we
inherit.
• Biological factors such as chromosomes, hormones and the brain all
have a significant influence on human behavior, for example, gender.
• The Biological perspective believes that most behavior is inherited
and has an adaptive (or evolutionary) function.

12. Behavior and Genetics
• Bio-psychologists study many of the same things that other psychologists
do, but they are interested in looking at how biological forces shape human
behaviors. Some topics
• Analyzing how trauma to the brain influences behaviors
• Assessing the differences and similarities in twins to determine which
characteristics are tied to genetics and which are linked to environmental
influences
• Exploring how genetic factors influence such things as aggression
• Investigating how degenerative brain diseases impact how people act
• Studying how genetics and brain damage are linked to mental disorders

13. Nature versus nurture
• The biological perspective is a way of looking at psychological issues
by studying the physical basis for animal and human behavior.
• One of the major debates in psychology has long centered over the
relative contributions of nature versus nurture.
• Those who take up the nurture side of the debate suggest that it is
the environment that plays the greatest role in shaping behavior.
• The biological perspective tends to stress the importance of nature.

15. Nature versus nurture

16. The immune system
• The immune system is a complex network of cells and proteins that
defends the body against infection.
• The organs and processes of the body that provide resistance to
infection and toxins.
• Organs include the thymus, bone marrow, and lymph nodes.
• The immune system keeps a record of every germ (microbe) it has
ever defeated so it can recognise and destroy the microbe quickly if it
enters the body again.

17. Human Nervous System
• Human is the most complex creator of this universe so all of his
systems are well developed, advance, and complex.
• Thus the nervous system is most complex, advance, and
efficient.

18. Neuron
• Neuron or nerve cell is the structural and functional unit of nervous system
• Specialized cells for the conduction of nerve impulses
• A neuron has three parts:
• Cell body; consists of cytoplasm and nucleus, a prominent nucleolus.
It also contains Golgi bodies, endoplasmic reticulum and ribosomes.
It provides nutrition to neuron.
• Dendrites; One or more short processes called dendrons which conduct impulses towards
the cell body
• Axon; It is a single long fiber, arises from the cell body.
It carries messages away from the cell body

20. Types of neurons
• Sensory or afferent neuron
• It carries messages from a sense organ to central nervous system.
• Motor or efferent neuron
• It takes messages from CNS to an effect or (muscle or gland)
• Associative or interneuron
• It takes impulse from sensory neuron and pass it to motor neuron

21. Human Nervous System
Central NS Peripheral NS
Brain Spinal Cord Somatic NS Autonomic NS
Parasympathetic NS
Sympathetic NS

22. Central Nervous System
• lies in the midline of body.
• consists of about 10 to 100 billion
neurons.
• concerned with judgment, thinking,
memory, emotions
• CNS consists of:
a. Brain
b. Spinal cord

23. Physiology and structure of the brain
• Biological psychologists explain behaviors in neurological terms, i.e.,
the physiology and structure of the brain and how this influences
behavior.
• Many biological psychologists have concentrated on abnormal
behavior and have tried to explain it.
• For example, biological psychologists believe that schizophrenia is
affected by levels of dopamine (a neurotransmitter).

24. Mental illness
• These findings have helped psychiatry take off and help relieve the
symptoms of mental illness through drugs.
• However, Freud and other disciplines would argue that this just treats
the symptoms and not the cause.
• This is where health psychologists take the finding that biological
psychologists produce and look at the environmental factors that are
involved to get a better picture.

25. • Weight: about 3 pounds
• Located in cranial cavity of skull
• Contains of billions of cells that integrate
information from inside and outside the
body, coordinate the body’s actions, and
enable human beings for various
functions
• Divisions of the brain
• Forebrain
• Mid Brain
• Hindbrain
Brain

26. Forebrain
The forebrain is the largest and most complex region of the brain,
consists of following structures:
a. Thalamus, sensory information (except smell)
b. Hypothalamus, basic biological needs
c. Limbic system, Amygdala (emotions) and Hippocampus
(memory)
d. Cerebrum, learning, memory, thinking, judgement, decision-
making and sensory information

27. Mid Brain
• lies between hindbrain and forebrain
• processing of visual and auditory information
• breathing, pain perception, regulation of sleep and arousal.

28. Pons
• bridge for conduction
of impulses between
cerebellum, medulla
oblongata, and
cerebrum.
• regulate the rate of
breathing
• sleep and wake cycle
Cerebellum
• little brain
• coorrdination of
movements
• balance and stability of
body
• learning new and motor
tasks
• if destroyed, movements
will be jerky and
disturbed.
• attaches to the spinal
cord
• controls unconscious
but vital functions such
as circulating blood,
breathing, maintaining
muscle tone,
sneezing, coughing,
and salivating
Medulla oblongata
Hind Brian

32. Glands and Types of Glands
• an organ which produces and releases substances that perform a specific function in
the body.
Types of Glands
• Exocrine Gland
These gland sends their secretions through ducts directly to target organs of the body.
The secretary products are enzymes, mucous and other substance.
• e.g. The important exocrine gland are salivary glands, liver, pancreas, sweat glands etc.
• Endocrine Gland
These gland are the ductless and their secretions that are hormones are directly poured
into the circulating blood and reach the organ.

33. What is Endocrine glands ?
• Group of ductless glands that regulate body processes by secreting
Hormones that act on nearby tissues or are carried in the
bloodstream to act on specific target organs and distant tissues.
• Functions
• Makes hormones that control your moods, growth and
development, metabolism, organs, and reproduction.
• Controls how your hormones are released
• Sends those hormones into your bloodstream so they can travel to other
body parts or target area.

34. In the context of psychology
• Endocrinology, which is the scientific study of the interaction
between hormones and behavior.
• In Gonads Hormones and Aggressive behaviour
• Dabbs , Hargrove, and Heusel (1996) measured the testosterone
levels on males to check their aggression level. They found that males
with the highest average testosterone levels were more wild and
unruly and males with the lowest average testosterone levels were
more well behaved, friendly and pleasant.

35. Hormones
• Hormones are chemical substances that act like messenger molecules in
the body.
• After being made in one part of the body, they travel to other parts of the
body where they help control how cells and organs do their work.
• For example, insulin is a hormone that's made by the beta cells in the
pancreas.
• Adrenal cortex is the outer region of kidney that secretes a specific
hormone called as Cortisol
• Cortisol the stress hormone
• The adrenal cortex releases a hormone called as Cortisol which activate in
stress condition. It has effect on cognitive functioning; at low level it
enhances memory and at high level cause memory impairement and
neuronal death.

36. Major Endocrine Glands
1. Pituitary Gland
2. Thyroid Gland
3. Parathyroid Gland
4. Adrenal Gland
5. Pancreas
6. Gonads
7. Pineal gland

38. Thanks